Cover unit with adapter, cover, and sealing film for a container

ABSTRACT

The invention relates to a cover unit ( 10 ) for closing and sealing a container ( 1 ). The opening ( 9 ) is surrounded by a sealing edge ( 8 ). The cover unit has an adapter ( 11 ), a cover ( 12 ), and a sealing film ( 13 ). The adapter can be arranged on the container in the opening thereof or around said opening so as to leave the sealing edge exposed, and the adapter has a through-opening ( 22 ). The cover is removably arranged on the adapter. The sealing film is clamped between the cover and the adapter so as to cover the through-opening. The invention also relates to a container with such a cover unit and to a method for sealingly closing a container.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a U.S. national stage application under 35U.S.C. §371 of International Application No. PCT/EP2013/051007, filedJan. 21, 2013, which claims priority to German Patent Application No.102012100483.8, filed Jan. 20, 2012, and German Patent Application No.102012209597.7, filed Jun. 6, 2012, the entireties of which areincorporated herein by reference.

FIELD OF DISCLOSURE

The present invention relates to a cover unit for closing and sealing anopening, which is surrounded by a sealing edge, of a container such as acan, barrel or the like, to a container closed using a cover unitaccording to the invention and having an opening surrounded by a sealingedge, and to a method for sealingly closing a container of this type.

BACKGROUND

Containers are known from the art in which an end-face opening is closedand sealed using a membrane. On the container, in the opening thereof, ametal ring is generally attached to the outer container wall by means ofa fold. The membrane is sealed onto the annular face of the metal ringfacing the outside of the container. The seal is completed by a pull-oncover, which covers the upper container edge, the metal ring and themembrane. One problem with containers or sealing systems of this type isthat during the manufacture of the metal ring a considerable proportionof the material used is wasted. So as to provide a suitably largecontainer opening for filling with and for withdrawing a fillingmaterial after being opened, the metal ring has a correspondingly largeclearance in the internal region thereof. The metal ring is produced bypunching it out from a metal sheet, and so the sheet material punchedout to form the internal recess becomes waste, which is inefficient,environmentally unfriendly and cost-intensive.

A container and sealing system are known in which the material use is infact reduced by comparison with the above-described prior art. A sealingmembrane is sealed directly onto the inner face of the container wall,in such a way that the aforementioned metal ring is not necessary.However, the system requires relatively high investment in facilitiesand machines, and attaching and sealing the sealing membrane to thegenerally curved inner wall of the container is generally not withoutdifficulties in terms of manufacture, for example as a result of weldseams in the wall. A further problematic aspect is that the sealing foilis attached to the inner container wall using an adhesive material.Therefore, after a user removes the sealing film, material residues maydisadvantageously remain on the inner wall of the container and inparticular in the region of the opening edge thereof. Also, 100% tightsealing of the container is generally not possible, and so it is onlysuitable for dry filling material.

SUMMARY OF THE INVENTION

Starting from the above-described prior art, the object of the inventionis to provide a cover unit and a method for closing and sealing acontainer by means thereof which are material-efficient, can beproduced/carried out on simple, conventional machines, and can be usedfor various commercially conventional containers and covers withoutadapting them to the invention. In particular, the cover unit is to besupplied as a pre-assembled unit to a filler of a correspondingcontainer, and, after filling with the filling material, should be ableto be arranged and sealed on the container by said filler in a simple,rapid and inexpensive manner using simple, conventional machines.

The object of the invention is achieved by a cover unit for closing andsealing, in particular sealing in a tamper-evident manner, an opening,which is surrounded by a sealing edge, of a container such as a can,barrel or the like, wherein the cover unit has an adapter, a cover, anda sealing film; the adapter can be arranged on the container in theopening thereof or around said opening so as to leave the sealing edgeexposed, and has a through-opening, the cover is arranged on the adapterin a removable manner, and the sealing film is clamped between the coverand the adapter so as to cover the through-opening.

The invention is further achieved by a container, which is closed usinga cover unit according to the invention, in particular according to anyone of the appended claims, and having an opening surrounded by asealing edge, wherein the sealing film is positioned peripherally on thesealing edge of the container, seals the opening thereof and inparticular is sealed tightly to the sealing edge.

Finally, the invention proposes a method for sealingly closing acontainer, such as a can, barrel or the like, wherein a cover unitaccording to any one of claims 1 to 7 is arranged on a container, inparticular according to any one of claims 8 to 13, having an opening anda sealing edge surrounding it, in the opening or around the opening insuch a way that the sealing film is positioned peripherally on thesealing edge, and the sealing film is sealed to the sealing edge bythermal action.

The invention relates in particular to two-part and three-partcontainers. A two-part container comprises a cover unit (as the firstpart) and a single-part container body (as the second part) closed orsealed thereby. The container body forms a container wall and containerbase in a single part, and can for example be manufacturedconventionally by deep-drawing or another shaping method. A three-partcontainer comprises a cover unit (as the first part) and a two-partcontainer body closed or sealed thereby and consisting of the containerwall (as the second part) and the container base (as the third part).The container wall and container base may for example be interconnectedby means of a fold.

The sealing film and the container are the only units which come intocontact with the filling material. The cover and the adapter cantherefore consist of virtually any desired materials, irrespective ofthe filling material. In this way, cost-effective and simple materialscan be used for the cover and adapter, whilst potentially high-gradematerials which are adapted to the filling material need only be usedfor the container and the sealing film, for example materials suitablefor food. The use of these expensive high-grade materials can thus bereduced. Preferably, the cover and/or adapter consist in whole or inpart of plastics material. The adapter may in particular be in the formof an injection-molded plastics material element. As a result, the lossof material described in the prior art from punching out a metal ringfor sealing film attachment can be prevented. The adapter is produced ina simple, cost-effective manner, for example injection-molded, in therespectively required shape.

Particularly advantageously, the cover unit can be pre-assembled fromthe adapter, cover and sealing film. It can be pre-assembled to seal asuitable container, and be arranged thereon in a particularly simplemanner after it is filled. Naturally, the adapter, cover and sealingfilm may also be arranged on the container individually to seal it. Inboth cases, the sealing film is laid on the adapter and the cover issubsequently arranged on the adapter, in such a way that the sealingfilm is positioned between the adapter and the cover and is clamped inplace and held at least until they seal it to the sealing edge. In thecase of the pre-assembled unit, the sealing film is subsequently (afterthe pre-assembly) arranged on the container, lying on the sealing edge,and sealed to the sealing edge thereof. In the other case, the adapteris arranged on the container before the sealing film is put on.

The cover is preferably arranged on the adapter using a thread or abayonet joint. As a result, the cover can be opened and reclosed in asimple manner by an end-user, in particular after the container isfilled and closed. Further, it can be arranged on the adapter using adetermined, defined contact pressure, in such a way that the sealingfilm is clamped in place and fixed sufficiently for sealing onto thesealing edge. It is advantageous for the cover to have some resilienceat least in part, for example in the region of the end-face cover facethereof, since in this case the sealing film can be reliably held by wayof a degree of yielding when it is placed on or screwed onto the adapterand the resulting resilient restoring force. According to the invention,a resilient intermediate layer which performs this resilient functioncan be laid in the cover on the adapter side between the sealing filmand the cover.

The adapter may be substantially annular in form or have a substantiallyannular wall, for example being in the form of a retainer ring. In thislast case, it is preferably provided internally or externally with thethread or the tappets of the bayonet connection. The adapter has anannular, interrupted or uninterrupted contact edge or contact face,which extends around in the cover when it is mounted on the adapter andcan, along with the sealing film, be pressed against a face of thecover, preferably against the end face thereof. The contact edge may forexample be the upper face of the adapter wall. It is particularlyadvantageous for the adapter edge to be formed by upper end regions ofcatch elements, which are disclosed in the following.

In one particular embodiment of the invention, the adapter comprisescatch elements, which hook together with a counter structure of thecontainer when said adapter is arranged correctly on the container.Advantageously, the adapter can be positioned and centered on thecontainer using the catch elements. At least three catch elements ofthis type are required so as to ensure definite radial positioning.Preferably, however, the adapter has a large number of these catchelements, which are arranged peripherally at small intervals, since inthis case particularly precise centering and positioning of the adapteron the container is possible. The adapter can be braced against thecontainer in the axial and/or radial direction by way of the catchelements. Preferably, the catch elements are arranged on the adapterusing a resilient web. In this way, they are mounted resiliently sprungwith respect to the adapter or the annular wall thereof. The web may forexample project radially and extend over a certain length in the axialdirection, in such a way that it has the corresponding springproperties. Particularly advantageously, the sealing film can be clampedbetween the adapter and cover by way of the catch elements, inparticular by way of the upper, cover-side end regions thereof.According to the invention, the catch elements may in particular beformed in that mutually separated incisions are made in the annular wallof the adapter and the catch elements themselves are formed by wallregions left behind between these incisions.

The container may be a conventional packaging container, preferably madeof metal, having a container base and a container wall, for example astandard can for coffee powder, milk powder and the like, but also formoist or wet filling materials. The container may in principle be of anydesired shape, preferably substantially cylindrical, and has a fillingopening which is enclosed by a sealing edge. This edge may be formed bya planar cut face of the container material or by a flanged region orflanged edge. It is particularly advantageous for the container to beprovided with a shoulder, preferably an oblique shoulder, at an axialdistance from the sealing edge or flanged edge. In this case, adepression or a plurality of depressions is/are formed between thesealing edge/flanged edge and the shoulder, preferably peripherally. Thecatch elements of the adapter subsequently engage therein when it isarranged on the container. Preferably, the flange or flanged edgeforming the sealing edge forms the counter piece which cooperates withthe catch elements. The shape of the catch elements is preferablyadapted to the shape of the container and in particular to the shape ofthe depression or neck region. The length of the catch elements maycorrespond to the height of the depression in the axial direction of thecontainer, or is slightly larger, in such a way that the end faces ofthe catch elements lie against the flanged edge of the sealing edge andthe opposing faces thereof lie against the shoulder of the depression.The axial position of the adapter and the catch elements is thus clearlydefined, and a defined contact pressure of the sealing film on the covervia the catch elements is ensured. In the radial direction, the adaptermay be braced on the container via the catch elements and/or via theannular wall.

To make it easier to slide the adapter onto the container, in a furtherinventive proposal said adapter comprises a ramp, preferably in the formof a shoulder extending in the radial and axial directions. This can lieagainst the shoulder of the container wall when the adapter is slid on.

In the container according to the invention, the sealing film is sealedto the sealing edge of the container. In a preferred embodiment, thesealing edge and sealing film are thermally fused together. According tothe invention, the sealing film may further be attached to the sealingedge using a hot adhesive. Finally, the sealing film may beself-adhesive. Thus, the only units of the container according to theinvention which come into contact with the filling material are thecontainer itself and the sealing film. The remaining units, such as theadapter, intermediate layer and cover, do not come into contact with thefilling material and can therefore be made of lower-quality materials,for example materials not suitable for food or resistant to the fillingmaterial.

In one embodiment of the invention, an anti-twist device is provided forthe cover unit with respect to the container. This may in principle beimplemented in a positive, non-positive or material fit. In particular,at least one catch structure may be arranged or formed in the region ofthe container wall on which the adapter is arranged, especially in theregion of the depression between the flanged edge and the shoulder. Thismay in particular project radially outwards, for example in the form ofa cam profile or a weld seam. When the cover unit is arranged on thecontainer, the catch elements of the catch structure on the containercooperate in a positive fit and bring about anti-twist protection of thecover unit on the container. In this context, the catch structure on thecontainer and the catch elements of the adapter engage in one another inthe radial direction and thus prevent the cover unit from twisting withrespect to the container. In another form of the invention, theanti-twist protection can be achieved in that the annular wall of theadapter is formed as an interference fit assembly or by means of a pressfit with respect to the container wall, in particular with respect tothe container wall on the side of the shoulder opposite the flangededge. Finally, the adapter may with respect to the container by means ofan adhesive or hot adhesive, in particular in the aforementioned region.This adhesion may be used as an alternative or in addition to the twotwist protections by positive and non-positive fit. Twist protection ofthis type ensures that the cover can be removed from and arranged backon the container by the user in a simple and reliable manner, in such away that the container can be opened and reclosed without difficulty.

The invention also relates to a method for sealingly closing acontainer, such as a can, barrel or the like, wherein a cover unitaccording to any one of the appended claims is arranged on a containerhaving an opening and a sealing edge surrounding said opening, in oraround the opening in such a way that the sealing film is positionedperipherally on the sealing edge, and the sealing film is sealed to thesealing edge by thermal action. As stated above, the cover unit may befully pre-assembled and be arranged on the container as a pre-assembledunit of this type. Alternatively, the adapter may initially be mountedon the container, the sealing film subsequently being laid on theadapter and clamped by arranging the cover on the adapter. In bothcases, the sealing film is subsequently sealed to the container.

Preferably, when the adapter is slid onto the container the latchelements thereof yield resiliently over a catch counter element,preferably in the form of a flanged edge, and spring back into theoriginal position thereof when the correct axial end position of theadapter on the container is reached, and hook onto the catch counterelement, preferably the flanged edge.

It is particularly preferred for the sealing edge and sealing film to beheated and sealed by induction, preferably by passing under a surfaceinduction coil. As a result of the invention, advantageously only thematerial of the sealing film has to be heated to a sufficienttemperature for the sealing. It is not necessary to apply an additionalcontact pressure to the container provided with the cover unit. Thecontact pressure on the sealing edge exerted on the sealing film by thecover and adapter is sufficient for the sealing, and so the devicerequired for sealing the container can advantageously be particularlysimple in construction and cost-effective. It is sufficient simply topass the container provided with the cover unit under an induction coiland merely to ensure sufficient heating.

In a further form of the invention, a hot adhesive is applied at leastto parts of the sealing edge and/or the sealing film, in particular inthat the cover unit passes through a hot adhesive application as apre-assembled unit. Alternatively, a self-adhesive film may be used.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention may be takenfrom the following exemplary description of a particularly preferredembodiment of the invention with reference to the drawings, in which:

FIG. 1 is a schematic plan view of a container according to theinvention provided with a cover unit,

FIG. 2 is a schematic sectional view of the container of FIG. 1 alongthe section line A-A,

FIG. 3 is an enlarged sectional view of the upper corner region markedin FIG. 2,

FIG. 4 is an exploded view of the container shown in FIGS. 1 to 3,

FIG. 5 is a partially sectioned container having a cover in a three-partembodiment having flanging,

FIG. 6 is a detail of the container of FIG. 5,

FIG. 7 is a partially sectioned container having a cover in a two-partembodiment, and

FIG. 8 is a detail of the container of FIG. 7.

DETAILED DESCRIPTION

FIG. 1 is a plan view of a metal container 1. It is of a substantiallycylindrical shape and has a container base 2 and a container wall 3. Thecontainer base 2 and container wall 3 are tightly interconnected by afold 4. As can be seen in particular in FIG. 3, the container wall 3 isformed into a neck portion 16 in the upper region thereof. The containerwall 3 here is deformed in the direction of the container interior andforms an oblique shoulder 5 and a peripheral depression 6. At the upperend, the container wall 3 is flanged to form a flanged edge 7, whichforms a sealing edge 8 on the face thereof remote from the containerbase 2. Said edge surrounds a filling opening 9 of the container 1.

The filling opening 9 is sealed by a cover unit 10, which has asubstantially annular adapter 11, a cover 12, a sealing film 13 and aresilient intermediate layer 14. The cover 12 and adapter 11 arereleasably screwed together via a thread 15. The cover unit 10 can beplaced on the neck region 16 of the container 1 as a pre-assembled unit,and placed in the state shown in FIGS. 1 to 3. The resilientintermediate layer 14 is inserted into the cover 12. The adapter has asubstantially annular wall 17, which is provided with the thread 15 onthe outside thereof. Radially obliquely inwardly resilient webs 18project from the wall 17 and form a ramp 23, and in turn each support acatch element 19. The upper end face 20 of the catch element 19, facingthe cover 12, is positioned at the level of the upper end face 21 of thewall 17 of the adapter 11, facing the cover 12. As is clear inparticular from FIG. 4, the catch elements 19 are formed peripherallywith equal spacing on the adapter 11. As a result of the resilience ofthe webs 18, they can spring resiliently in the radial direction.

In the pre-assembled state, the sealing film 13 is held clamped betweenthe cover 12 and the adapter 11, in such a way that it is positioneddirectly on the sealing edge 8 when the cover unit 10 is arranged on thecontainer 1, and preferably pressed on with the necessary pressure forthe sealing. In the preassembled state, it is in contact with theresilient intermediate layer 14 and the upper end face 20 of the catchelements 19 formed on the adapter 11 and/or the upper end face 21 of thewall 17 of the adapter 11. The adapter 11 is formed in such a way thatit does not cover the sealing edge 8 or only covers it in part, and thesealing film 13 is positioned directly on the entire sealing edge 8 orsub-regions thereof after the cover unit 10 is mounted on the container.

When the pre-assembled cover unit 10 is slid onto the container 1, theflanged edge 7 penetrates into the interior enclosed by the wall 17 ofthe adapter 11, until it is struck by the webs 18. During furthersliding on, the webs 18 and the catch elements arranged thereon springoutwards in the radial direction. The cover unit 10 can therefore beslid further over the flanged edge 7. When the axial end position shownin FIG. 3 is reached, the latch elements 19 snap back into the originalpositions thereof as a result of the resilience of the webs 18, and thushook onto the flanged edge 7, in such a way that the cover unit 10 isattached to the container 1 in a radially and axially defined manner.Shortly before this end position is reached, the sealing film 13 comesinto contact with the sealing edge 8. Because the resilient intermediatelayer 14 yields slightly, it becomes possible to slide the cover unitfurther onto the container 1, until the catch elements 19 snap in.Instead of the resilient intermediate layer 14, a degree of resilienceof the cover 12 itself may ensure this, in which case the intermediatelayer can be omitted. In both cases, the sealing film 13 is secured andattached to the sealing edge when the cover unit 10 is fully slid on.Subsequently, the sealing film 13 is sealed and attached by heating fromabove or from the side of the sealing region, for example by induction.

The end user opens the container 1 by unscrewing the cover 12 from theadapter 11 and thus from the container 1. Subsequently, the sealing film13 is freely accessible, and the container can be definitively andcompletely opening by pulling it off. It can subsequently be sealedagain by screwing on the cover 12. To make it easier to screw on andunscrew the cover 12, the adapter 11 is secured against twisting withrespect to the container by stops (not shown in the drawings).

FIGS. 2, 4, 5 and 6 show the container in a three-part embodiment, inwhich the container base 2 as the first part and the container wall 3 asthe second part are interconnected by means of the flange 4. The coverunit 10 forms the third part. FIGS. 7 and 8 show the container 1 in avariant, specifically a two-part embodiment, in which the container 1 asa first part is formed with the container base 2 and container wall 3 ina single part. In this variant, the cover unit 10 forms the second part.In the variant of FIGS. 7 and 8, the container 1 is produced bydeep-drawing.

1. Cover unit (10) for closing and sealing an opening (9) of a container(1), the opening being surrounded by a sealing edge (8), the containersuch as a can, barrel or the like, wherein the cover unit (10) has anadapter (11), a cover (12), and a sealing film (13), the adapter (11) isconfigured for arrangement the container (1) in the opening (9) thereofor around the opening (9) so as to leave the sealing edge (8) exposed,and has a through-opening (22), the cover (12) is removably arranged onthe adapter (11) and the sealing film (13) is clamped between the cover(12) and the adapter (11) so as to cover the through-opening (22)thereof.
 2. Cover unit according to claim 1, wherein the adapter (11)and the cover (12) are interconnected using a thread (15) or a bayonetjoint.
 3. Cover unit according to either claim 1 or claim 2, wherein theadapter (11) comprises catch elements (19), which hook together with acounter structure (7) of the container (1) when said adapter (11) isarranged correctly on the container (1).
 4. Cover unit according to anyone of the preceding claims, wherein the adapter (11) comprises a ramp(23), preferably in the form of a shoulder extending in the radial andaxial directions.
 5. Cover unit according to either claim 3 or claim 4,wherein the catch elements (19) are arranged on the adapter (11) using aresilient web (18).
 6. Cover unit according to any one of the precedingclaims, further comprising a resilient intermediate layer (14), which isarranged between the cover (12) and the sealing film (13).
 7. Container,dosed using a cover unit according to any one of the preceding claimsand having an opening (9) surrounded hy a sealing edge (8), wherein thesealing film (13) is positioned circumferentially on the sealing edge(8) of the container (1), closing the opening (9) thereof and is sealedto the sealing edge (8).
 8. Container according to claim 7, comprising aflanged edge (7), which cooperates with catch elements (19) of theadapter (11) and fixes it to the container (1).
 9. Container accordingto claim 8, comprising an oblique shoulder (5) at a distance from theflanged edge (7), the distance between the oblique shoulder (5) and theflanged edge (7) being equal to or slightly less than the distancebetween a ramp (23) of the adapter (11) and the upper edge (20, 21)thereof.
 10. Container according to any one of claims 7 to 9, whereinthe sealing edge (8) and sealing film (13) are thermally fused together.11. Container according to any one of claims 7 to 10, wherein the coverunit (10) is secured against twisting with respect to the container (1),in particular by positive fit, non-positive fit and/or adhesion. 12.Container according to claim 11, wherein catch elements (19) cooperatein a positive fit with a catch structure, which is in particular in theform of a cam profile or weld seam, projects radially outwards, and isarranged between the flanged edge (7) and the shoulder (5) of thecontainer (1) in the axial direction of the container.
 13. Containeraccording to either claim 11 or claim 12, wherein the adapter (17), inparticular an annular wall (17) of the adapter (11), is arranged on acontainer wall (3) of the container (1) by means of a press fit. 14.Method for sealingly closing a container (1), such as a can, barrel orthe like, wherein a cover unit (10) according to any one of claims 1 to7 is arranged on a container (1), in particular according to any one ofclaims 8 to 13, having an opening (9) and a sealing edge (8) surroundingthe opening, in the opening (9) or around the opening (9) in such a waythat the sealing film (13) is positioned circumferentially on thesealing edge (8), and the sealing film (13) is sealed to the sealingedge (8) by thermal action.
 15. Method according to claim 14, whereinthe cover unit (10) is fully pre-assembled and is arranged on thecontainer (1) as a pre-assembled unit of this type.
 16. Method accordingto either claim 14 or claim 15, wherein when the adapter (11) is slidonto the container (1) latch elements (19) thereof yield resilientlyover a catch counter element, preferably in the form of a flanged edge(7), and spring back into the original position thereof when the correctaxial end position of the adapter (11) on the container (1) is reached,and hook onto the catch counter element, preferably the flanged edge(7).
 17. Method according to any one of claims 14 to 16, wherein thesealing edge (8) and sealing film (13) are heated and sealed byinduction, preferably by passing under a surface induction coil. 18.Method according to any one of claims 14 to 17, wherein a hot adhesiveis applied at least to parts of the sealing edge (8) and/or the sealingfilm (13), in particular in that the cover unit (10) passes through ahot adhesive application as a pre-assembled unit.